For the pudding: Preheat the oven to 350 degrees F. Lightly spray a 2-quart baking dish with nonstick cooking spray.
Whisk together the eggs, milk, cream, granulated sugar, vanilla and salt in a large bowl. Pour in the bread and chocolate chips. Toss until the bread is coated on all sides and the chocolate is distributed. Pour into the prepared baking dish. Bake until puffed and golden brown, 45 to 50 minutes.
For the sauce: Meanwhile, place a small saucepot over medium-high heat. Set aside 1 tablespoon of the orange juice. Pour the remaining orange juice and sugars into the saucepot and whisk until combined. Bring to a simmer and simmer, whisking occasionally, until the sugars dissolve, about 10 minutes.
Whisk together the reserved orange juice and cornstarch in a small bowl. Pour into the sauce and whisk until combined. Cook until the sauce becomes syrupy, about 5 minutes. Stir in the orange zest. The sauce will thicken more as it cools. Pour the warm sauce over the pudding and serve.